Ironman

This article is timeless and should be accurate for any version of the game.

Ironman is an optional game mode that restricts the player's control over their save file, effectively removing the ability to correct mistakes or change decisions made during the course of play. Ironman can be enabled from the settings screen when starting a new campaign.

The "Steam Cloud" option must be enabled for the game in the Steam library (Hearts of Iron IV/Properties/Updates). This also requires that "Enable Steam Cloud synchronization for applications which support it" is enabled in the Steam settings (Steam/Settings/Cloud).